Multi-column graphite-over-foam assembly

Abstract

A multi-column graphite-over-foam (GOF) assembly includes a plurality of foam columns wherein each foam column of the plurality of foam columns are individually wrapped in a graphite sheet. A graphite layer surrounds the plurality of foam columns and an electrically conductive outer layer surrounding the graphite layer. The graphite layer is configured to thermally couple the electrically conductive outer layer to the plurality of foam columns, and the electrically conductive outer layer is configured to absorb electromagnetic interference (EMI).

What is claimed is: 
     
       1. A multi-column graphite-over-foam (GOF) assembly comprising:
 a plurality of foam columns, each foam column of the plurality of foam columns being individually wrapped in a graphite sheet; 
 a graphite layer surrounding the plurality of foam columns; and 
 an electrically conductive outer layer surrounding the graphite layer, 
 wherein the graphite layer thermally couples the electrically conductive outer layer to the plurality of foam columns, and 
 wherein the electrically conductive outer layer is exposed to an exterior environment of the multi-column GOF assembly to absorb electromagnetic interference (EMI) and direct heat to the plurality of foam columns via the graphite layer, the multi-column GOF assembly is positioned on a printed circuit board (PCB), and foam columns of the plurality of foam columns are stacked adjacent to one another along a first axis, perpendicular to a second axis along which additional foam columns of an additional plurality of foam columns of an additional multi-column GOF assembly positioned on the PCB are stacked adjacent to one another. 
 
     
     
       2. The multi-column GOF assembly of  claim 1 , wherein the electrically conductive outer layer is configured to surround a heat source and electrically couple the PCB to a chassis housing. 
     
     
       3. The multi-column GOF assembly of  claim 2 , wherein the multi-column GOF assembly is configured to be compressed between the heat source and a lid of the chassis housing. 
     
     
       4. The multi-column GOF assembly of  claim 3 , wherein the multi-column GOF assembly conducts heat and the EMI from the heat source to the chassis housing. 
     
     
       5. The multi-column GOF assembly of  claim 1 , wherein the electrically conductive outer layer electrically couples to the PCB through contacts surrounding a heat source and/or an EMI shield surrounding the heat source. 
     
     
       6. The multi-column GOF assembly of  claim 1 , wherein the electrically conductive outer layer is disposed on a side of the multi-column GOF assembly configured to contact a heat source. 
     
     
       7. The multi-column GOF assembly of  claim 1 , wherein the electrically conductive outer layer surrounds at least four sides of the multi-column GOF assembly. 
     
     
       8. The multi-column GOF assembly of  claim 1 , wherein the graphite sheet of each of the plurality of foam columns is configured to conduct heat through the multi-column GOF assembly. 
     
     
       9. The multi-column GOF assembly of  claim 2 , wherein the electrically conductive outer layer is configured to cover the heat source. 
     
     
       10. The multi-column GOF assembly of  claim 2 , wherein the electrically conductive outer layer is configured to contact ground pins surrounding the heat source. 
     
     
       11. A system comprising:
 a printed circuit board (PCB); 
 a chassis receiving the PCB, the chassis comprising a lid with a plurality of separate, independent grounds disposed thereon; 
 a heat source disposed on the PCB; and 
 a multi-column graphite-over-foam (GOF) assembly that:
 presses against the heat source to cover and surround the heat source such that the multi-column GOF assembly electrically couples to a plurality of ground pins of the PCB surrounding the heat source, 
 thermally couples the heat source to the chassis, and
 absorbs electromagnetic interference (EMI) from the heat source an conducts the EMI to the chassis, 
 
 
 wherein the lid is coupled to walls of the chassis, and coupling of the lid to the walls of the chassis rotationally aligns a particular ground of the plurality of separate, independent grounds to the multi-column GOF assembly to electrically couple the multi-column GOF assembly to the particular ground. 
 
     
     
       12. The system of  claim 11 , wherein the multi-column GOF assembly comprises:
 a plurality of columns, each column of the plurality of columns comprising a foam core individually wrapped in a graphite sheet; 
 a graphite layer surrounding the plurality of columns; and 
 an electrically conductive outer layer disposed between the graphite layer and the heat source. 
 
     
     
       13. The system of  claim 12 , wherein the electrically conductive outer layer and the graphite layer are configured to spread heat received from the heat source to the plurality of columns. 
     
     
       14. The system of  claim 12 , wherein the plurality of columns are configured to conduct heat through the multi-column GOF assembly towards a heatsink of the chassis. 
     
     
       15. The system of  claim 12 , further comprising an EMI shield surrounding the heat source, wherein the electrically conductive outer layer is electrically coupled to the EMI shield. 
     
     
       16. The system of  claim 11 , wherein each ground of the plurality of separate, independent grounds comprises a respective ground circuit. 
     
     
       17. A method comprising:
 compressing a first multi-column graphite-over-foam (GOF) assembly between a printed circuit board (PCB) and a housing to cover and surround a heat source on the PCB to electrically couple the first multi-column GOF assembly to a plurality of ground pins surrounding the heat source, wherein the first multi-column GOF assembly comprises a first plurality of foam columns stacked adjacent to one another along a first axis; 
 compressing a second multi-column GOF assembly between the PCB and the housing to cover and surround an additional heat source on the PCB to electrically couple the second multi-column GOF assembly to an additional plurality of ground pins surrounding the additional heat source, wherein the second multi-column GOF assembly comprises a second plurality of foam columns stacked adjacent to one another along a second axis, perpendicular to the first axis; 
 conducting heat, via respective thermally conductive sheets traversing the first multi-column GOF assembly and the second multi-column GOF assembly, from the heat source and from the additional heat source on the PCB to a heatsink on the housing; 
 absorbing, via a respective electrically conductive wrap of the first multi-column GOF assembly and of the second multi-column GOF assembly, an electromagnetic interference (EMI) emitted by the heat source and by the additional heat source; and 
 conducting, via the respective electrically conductive wrap of the first multi-column GOF assembly and of the second multi-column GOF assembly, the EMI to the plurality of ground pins and to the additional plurality of ground pins. 
 
     
     
       18. The method of  claim 17 , further comprising spreading, via a respective graphite wrap of the first multi-column GOF assembly and of the second multi-column GOF assembly, the heat from the heat source and from the additional heat source to the respective thermally conductive sheets. 
     
     
       19. The method of  claim 17 , further comprising electrically coupling the PCB to the housing via the respective electrically conductive wrap of the first multi-column GOF assembly and of the second multi-column GOF assembly. 
     
     
       20. The method of  claim 17 , wherein the housing comprises separate, independent, respective ground circuits disposed on a lid of the housing, and the compressing of the first multi-column GOF assembly between the PCB and the housing and the compressing of the second multi-column GOF assembly between the PCB and the housing comprise pressing the first multi-column GOF assembly and the second multi-column GOF assembly into contact with the separate, independent, respective ground circuits.